Last time I was haulin a trailer I was pullin a 13k lb dump trailer and with my chip on high I could not keep the truck coolant very cool.was about ready to overheat. It runs about 190 all the time when not pullin and the fan runs alot.. I dont think it should run that hot when just drivin around. Maby i need to replace the thermostate. I cleaned the radiator and intercooler but it still run to hot I think. Is this normal to run that hot or am i just . Thanks

Last time I was haulin a trailer I was pullin a 13k lb dump trailer and with my chip on high I could not keep the truck coolant very cool.was about ready to overheat. It runs about 190 all the time when not pullin and the fan runs alot.. I dont think it should run that hot when just drivin around. Maby i need to replace the thermostate. I cleaned the radiator and intercooler but it still run to hot I think. Is this normal to run that hot or am i just . Thanks

before i did my radiator flush and fill, my average coolant temp when empty was ~145. i might have hit 190 when pulling a heavy trailer. when i did the flush and fill, i replaced the thermostat with a oreilly's thermostat(murry was the brand name). after that my temps are 185-195 empty, and 190-200 with a trailer. the thermostats where not the EXACT same dimensions, but fit and the springs where much stiffer. like you, i was also concerned. after asking some people, everyone said i was normal. if i was you i would make sure or radiator isn't plugged and free from defects. maybe you could find a "cooler" thermostat?

--- Update to the previous post...

here's the link to the thread i had

http://forum.mopar1973man.com/showthread.php/1840-engine-coolant-flush

How much did the new thermostate cost you?

--- Update to the previous post...

I did clean the radiator and the intercooler.

Along the lines of the above mentioned, have you ever drained and flushed the cooling system and replaced the coolant? Over time the coolant can break down and allow corrosion to restrict or plug up the raditiator cores. Sometimes when this happens, the only option is a new radiator or to rod and hot tank the radiator. The other possibility is the water pump.

Typically in my truck Edge Comp on 5x5 and RV275 injectors hauling 2 cords of firewood I vary from 193*F to 197*F. You might read my thread... http://forum.mopar1973man.com/showthread.php/2241-Radiator-cleaning...

i wouldn't run a chip or fueling box on high and i would only recommend using the 190* stat..per cummins shop foremans.

The cooling systems on these trucks is so large that under light loads the thermostat never opens fully, and this creates a wear mark on the shaft and sometime after lots of miles the thermostat loses the ability to fully open. You also get a lot more cycles of the thermostat when your not loaded all the time, so the spring weakens and starts to react slower. I changed my thermostat at 48K miles and it made a HUGE difference. Pre-change I could see 202-207* spikes on initial thermostat opening, then I would run normal. Now I see 195-197* spikes on initial opening. Mine hadn't developed a wear spot, but it did react slower, and it really had very few miles on it.I think a thermostat is about $30 from Cummins. I would only run genuine Cummins, and 190* is what came stock so that's what I run.

As for t-stat replacement... I've been changing mine every year at 30K miles at flush time so I've never had a issue with overheating or such. But I've been using a NAPA t-stat without any issue...

Ok.. So i am gonna flush the system and replace the t-stat that outta fix my problem. How much anti freeze does the whole system hold?? . Thanks you guys been alot of help:thumb1:

Book says 26 quarts or 6.5 gallons.

Actually you'll only get about 5 to 5.5 gallons in typically... There is a bit of water that you just can't get out of the block...

ok thanks. now I know what im gonna need ahead of time..

I parked my truck nose down on a very steep incline and got about 5.5 gallons out of mine. I replaced my coolant with Shell Extended Life Coolant 50/50 Premix.

Actually you'll only get about 5 to 5.5 gallons in typically... There is a bit of water that you just can't get out of the block...

Yep. So on that note add the coolant first and add half of the capacity, then fill with distilled water. I would never use pre-mix in a Cummins, they just don't drain enough out and your coolant will be too thin. My system holds 7.4 gallons, but a normal drain only gets about 5 gallons out. So if I used premix the ratio would be 33% coolant, well below the 44% coolant minimum Cummins/Mopar has established.

Maybe I got more than that out on the slope. After I was done, I checked the coolant with a coolant tester and it was good well into the negative numbers, I forgot exactly how much but it was enough that I am not concerned that it will ever get that cold in the lower 48 states.

I did jack my rear end up about 6" and got a qt or two more out, so I could see where a good slope would get more. As for the 44% min, from the service manual: If percentage is lower than 44 percent, engine parts may beeroded by cavitation, and cooling system componentsmay be severely damaged by corrosion.A 50:50 ratio is good for -37*F.

If you've not done Mikes breather/puke vent mod, you've probably got an oily, slimy mess covering the cooling fins on your radiator, intercooler and trans cooler. When I had my '99, I used to spray down the radiator etc. with a mixture of simple green and water. I'd let it sit a while and then spray it out. Made for a cooler running truck in short order.

I do need to do that. Do you got to remove the intercooler to get at the radiator compleatly? Sounds like a pain to do..

Radiator is easy to pull out... (Manual Trans)

[*]Drain the coolant

[*]Pull the upper and lower hoses

[*]Remove the coolant bottom (lift upwards)

[*]Remove the wiper fluid bottle (Disconnect the hose, electrical, and the sensor then using a screwdriver to release the bottle from the shroud. CAREFULLY!)

[*]4 10mm bolts & 2 clips holding the shroud slide it on the fan.

[*]2 10mm bolts holding the radiator. (Lift!)

* Auto trans will have cooler lines on the tank header to remove before. This should be done after the shroud is remove to give more access.

* No intercooler removal required!

Pics back here..

http://forum.mopar1973man.com/showthread.php/2241-Radiator-cleaning

I do need to do that. Do you got to remove the intercooler to get at the radiator compleatly? Sounds like a pain to do..

yep!!!

R

[*]Remove the coolant bottom (lift upwards)

[*]Remove the wiper fluid bottle (Disconnect the hose, electrical, and the sensor then using a screwdriver to release the bottle from the shroud. CAREFULLY!)

Yeah - that friggin windscreen wiper bottle is a PIA if you haven't done before - ISX even showed me once - but I till struggled the next time - because of those two tabs that lock it into place - the screwdriver trick is the key - or having someone to push in whilst you lift up and out

everything always seems so simple when someone else does it ........